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ifstream into array problem

RobTTay (5)
So i made a program that fills an array with random numbers and then puts those random numbers into a txt file.
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#include <iostream>
#include <fstream>
#include <cstdlib>
#include <ctime>
using namespace std;

int main()
{
    ofstream outputFile;
    unsigned seed = time(0);
    srand(seed);
    int numList[100];

    for(int i=0; i < 100; i++)
    {
        numList[i] = rand()%100+1;
    }

    outputFile.open("NumbersWrite.txt");

    for(int i=0; i<100; i++)
    {
        outputFile << numList[i];
    }

    return 0;
}


Then i made a second program that's supposed to read the numbers from the txt file and put them into an array and calculate the total and average.
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#include <iostream>
#include <fstream>
#include <cstdlib>
using namespace std;

int printElements(int array[]);
int main()
{
    int total;
    int average;
    ifstream in;
    int array[100];
    int i=0;

    in.open("NumbersWrite.txt");

    while(! in.eof())
    {
       in >> array[i];
       i++;
    }

    total = printElements(array);
    average = total / 100;
    cout << "Total: " << total << "\n";

}
//*******************************************************
int printElements(int array[])
{
    int total = 0;
    int i = 0;
    cout << "\n\n";
    for (i=0; i<100; i++)
    {
        cout << array[i] << ",";
        total = total + array[i];
    }
    cout << "\n\n";
    return total;
}
//********************************************************


but for some reason the second program gives me the output



2147483647,4703424,4206395,4661576,-1,2686332,761488231,4661576,4705684,6,466032
8,0,2686524,2,4705684,0,4660328,2686696,4251833,0,6,4661576,4705684,4660328,4705
684,2686428,4290022,4640780,2686524,1,4705684,6,0,6,16,1,4200860,4635612,4683024
,4682916,0,2686696,0,7933560,7933560,2686568,1987835008,7929856,0,1987835017,-42
7065163,16,7933576,7933560,2001271530,2001408146,-1,36,0,7933560,7933560,2686632
,1987835008,7929856,0,1987835017,-427065227,20,7933580,7933560,2001271530,200140
8146,-1,36,2686616,4,0,-458310117,2686632,1987835392,0,0,0,2686652,1987814466,19
88428456,2686716,1987835090,8,1987842446,1987842402,-427065311,0,0,0,4286272,268
6672,2686728,2686916,1987939541,

Total: 1192635174

Process returned 0 (0x0) execution time : 0.080 s
Press any key to continue.


The numbers look nothing like the one's in the text file.
Could you explain why and how to fix it
any help would be greatly appreciated.
kbw (9488)
You haven't written delimiters into the file. Did you look at it?

If you want a number per line you'd write:
 
 
outputFile << numList[i] << std::endl;


Don't declare file objects at the top of your functions, then open them later. Declare objects where they're used.

Also, think of a file as a stream. So forget about "end of file" or "opening a file", think of whether the stream is in a usable state.
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int main()
{
    unsigned seed = time(0);
    srand(seed);
    int numList[100];

    for(int i=0; i < 100; i++)
    {
        numList[i] = rand()%100+1;
    }

    ofstream outputFile("NumbersWrite.txt");
    for (int i=0; i<100; i++)
    {
        outputFile << numList[i] << endl;
    }

    return 0;
}

and
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int main()
{
    int array[100];
    int i=0;

    ifstream in("NumbersWrite.txt");
    while (in)
    {
        in >> array[i++];
    }

    int total = printElements(array);
    int average = total / 100;
    cout << "Total: " << total << "\n";
}
Last edited on
RobTTay (5)
Thank you so much.
It seems that whenever i post something on here it's something as simple as this.

I declare all of my file objects at the start because my teacher requests it, he likes it formatted that way.
kbw (9488)
I declare all of my file objects at the start because my teacher requests it, he likes it formatted that way.
It violates in important principle (RAII) and causes a different flow in the presence of exceptions.
https://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization
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